$ { \left[\begin{array}{rr}{2} & {1} \\ {3} & {-1} \\ {-2} & {0}\end{array}\right]+\left[\begin{array}{rr}{0} & {3} \\ {0} & {0} \\ {4} & {-1}\end{array}\right] = {?} } $
Solution: To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rr}{2}+{0} & {1}+{3} \\ {3}+{0} & {-1}+{0} \\ {-2}+{4} & {0}+{-1}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{2} & {4} \\ {3} & {-1} \\ {2} & {-1}\end{array}\right]}$